1. Technical Field
Example embodiments of the present invention relate in general to an optical transmitter module, and more particularly, to an optical transmitter module for minimizing impedance mismatch occurring therein.
2. Related Art
With the recent increase in data transmission through a communication network, such as the Internet, existing data transmission systems employing an electrical signal are required to have an increased transmission amount and transmission speed of data. Accordingly, use of optical communication systems capable of transmitting a large amount of data at high speed is increasing. Optical devices constituting such an optical communication system include an optical fiber that transfers a light signal, an optical transmitter module that generates and emits the light signal to the optical fiber, an optical receiver module that receives the light signal transferred through the optical fiber, an optical splitter that distributes or split the received light, and so on.
The optical transmitter module may include a thermoelectric cooler (TEC) to stabilize a wavelength. Such a TEC may stabilize a wavelength by controlling the temperature in the optical transmitter module. When a TEC is used, a laser diode (LD) and a reflecting mirror are positioned on the TEC. The LD is connected to a lead pin by wire bonding.
Methods of coupling the lead pin to a package may be classified into transistor outline (TO)-type feed-through and butterfly-type feed-through. In the case of the TO-type feed-through, when the height of the TEC increases, a mismatch section of the lead pin lengthens, and thus the quality of a signal transmitted by the optical transmitter module deteriorates.
In the case of the butterfly-type feed-through, unlike the TO-type feed-through, the mismatch section of the lead pin does not lengthen in proportion to the height of the TEC. However, for wire bonding with the LD, the lead pin is required to protrude from the package by a predetermined length. Therefore, there is a mismatch section whose length corresponds to the length of a portion of the lead pin protruding from the package, and the quality of a signal transmitted by the optical transmitter module deteriorates.